//////////package mysql;
//////////
//////////public class mysql {
//////////}
//////////
//////////
//////////Enter password: *********
//////////Welcome to the MySQL monitor.  Commands end with ; or \g.
//////////Your MySQL connection id is 8
//////////Server version: 8.0.39 MySQL Community Server - GPL
//////////
//////////Copyright (c) 2000, 2024, Oracle and/or its affiliates.
//////////
//////////Oracle is a registered trademark of Oracle Corporation and/or its
//////////affiliates. Other names may be trademarks of their respective
//////////owners.
//////////
//////////        Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
//////////
//////////mysql> use java113;
//////////Database changed
//////////mysql> show tables;
//////////+----------------------------------+
//////////        | Tables_in_java113                |
//////////        +----------------------------------+
//////////        | class                            |
//////////        | course                           |
//////////        | emp                              |
//////////        | score                            |
//////////        | stu2                             |
//////////        | student                          |
//////////        | test1                            |
//////////        | test2                            |
//////////        | test3                            |
//////////        | test4                            |
//////////        | view_student_class_course_score1 |
//////////        +----------------------------------+
//////////        11 rows in set (0.03 sec)
//////////
//////////mysql> insert into account values (null, '张三', 1000), (null, '李四', 900);
//////////Query OK, 2 rows affected (0.04 sec)
//////////Records: 2  Duplicates: 0  Warnings: 0
//////////
//////////mysql> select * from account;
//////////+----+--------+---------+
//////////        | id | name   | balance |
//////////        +----+--------+---------+
//////////        |  1 | 张三   |    1000 |
//////////        |  2 | 李四   |     900 |
//////////        +----+--------+---------+
//////////        2 rows in set (0.00 sec)
//////////
//////////mysql> show engines;
//////////+--------------------+---------+----------------------------------------------------------------+--------------+------+------------+
//////////        | Engine             | Support | Comment                                                        | Transactions | XA   | Savepoints |
//////////        +--------------------+---------+----------------------------------------------------------------+--------------+------+------------+
//////////        | MEMORY             | YES     | Hash based, stored in memory, useful for temporary tables      | NO           | NO   | NO         |
//////////        | MRG_MYISAM         | YES     | Collection of identical MyISAM tables                          | NO           | NO   | NO         |
//////////        | CSV                | YES     | CSV storage engine                                             | NO           | NO   | NO         |
//////////        | FEDERATED          | NO      | Federated MySQL storage engine                                 | NULL         | NULL | NULL       |
//////////        | PERFORMANCE_SCHEMA | YES     | Performance Schema                                             | NO           | NO   | NO         |
//////////        | MyISAM             | YES     | MyISAM storage engine                                          | NO           | NO   | NO         |
//////////        | InnoDB             | DEFAULT | Supports transactions, row-level locking, and foreign keys     | YES          | YES  | YES        |
//////////        | ndbinfo            | NO      | MySQL Cluster system information storage engine                | NULL         | NULL | NULL       |
//////////        | BLACKHOLE          | YES     | /dev/null storage engine (anything you write to it disappears) | NO           | NO   | NO         |
//////////        | ARCHIVE            | YES     | Archive storage engine                                         | NO           | NO   | NO         |
//////////        | ndbcluster         | NO      | Clustered, fault-tolerant tables                               | NULL         | NULL | NULL       |
//////////        +--------------------+---------+----------------------------------------------------------------+--------------+------+------------+
//////////        11 rows in set (0.01 sec)
//////////
//////////mysql> select * from account;
//////////+----+--------+---------+
//////////        | id | name   | balance |
//////////        +----+--------+---------+
//////////        |  1 | 张三   |    1000 |
//////////        |  2 | 李四   |     900 |
//////////        +----+--------+---------+
//////////        2 rows in set (0.00 sec)
//////////
//////////mysql> start transaction;
//////////Query OK, 0 rows affected (0.01 sec)
//////////
//////////mysql> update account set balance = balance - 100 where name = '张三';
//////////Query OK, 1 row affected (0.01 sec)
//////////Rows matched: 1  Changed: 1  Warnings: 0
//////////
//////////mysql> update account set balance = balance + 100 where name = '李四';
//////////Query OK, 1 row affected (0.00 sec)
//////////Rows matched: 1  Changed: 1  Warnings: 0
//////////
//////////mysql> select * from account
//////////    -> ;
//////////            +----+--------+---------+
//////////            | id | name   | balance |
//////////        +----+--------+---------+
//////////        |  1 | 张三   |     900 |
//////////        |  2 | 李四   |    1000 |
//////////        +----+--------+---------+
//////////        2 rows in set (0.00 sec)
//////////
//////////mysql> rollback;
//////////Query OK, 0 rows affected (0.03 sec)
//////////
//////////mysql> select * from balance;
//////////ERROR 1146 (42S02): Table 'java113.balance' doesn't exist
//////////mysql> select * from select;
//////////ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'select' at line 1
//////////mysql> select * from balance;
//////////ERROR 1146 (42S02): Table 'java113.balance' doesn't exist
//////////mysql> show tables;
//////////+----------------------------------+
//////////        | Tables_in_java113                |
//////////        +----------------------------------+
//////////        | account                          |
//////////        | class                            |
//////////        | course                           |
//////////        | emp                              |
//////////        | score                            |
//////////        | stu2                             |
//////////        | student                          |
//////////        | test1                            |
//////////        | test2                            |
//////////        | test3                            |
//////////        | test4                            |
//////////        | view_student_class_course_score1 |
//////////        +----------------------------------+
//////////        12 rows in set (0.00 sec)
//////////
//////////mysql> select * from account;
//////////+----+--------+---------+
//////////        | id | name   | balance |
//////////        +----+--------+---------+
//////////        |  1 | 张三   |    1000 |
//////////        |  2 | 李四   |     900 |
//////////        +----+--------+---------+
//////////        2 rows in set (0.00 sec)
//////////
//////////mysql> start transection;
//////////ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'transection' at line 1
//////////mysql> start transaction;
//////////Query OK, 0 rows affected (0.00 sec)
//////////
//////////mysql> select * from account;
//////////+----+--------+---------+
//////////        | id | name   | balance |
//////////        +----+--------+---------+
//////////        |  1 | 张三   |    1000 |
//////////        |  2 | 李四   |     900 |
//////////        +----+--------+---------+
//////////        2 rows in set (0.00 sec)
//////////
//////////mysql> update account set balance = balance - 100 where name = '张三';
//////////Query OK, 1 row affected (0.00 sec)
//////////Rows matched: 1  Changed: 1  Warnings: 0
//////////
//////////mysql> update account set balance = balance + 100 where name = '李四';
//////////Query OK, 1 row affected (0.00 sec)
//////////Rows matched: 1  Changed: 1  Warnings: 0
//////////
//////////mysql> select * from account;
//////////+----+--------+---------+
//////////        | id | name   | balance |
//////////        +----+--------+---------+
//////////        |  1 | 张三   |     900 |
//////////        |  2 | 李四   |    1000 |
//////////        +----+--------+---------+
//////////        2 rows in set (0.00 sec)
//////////
//////////mysql> commit;
//////////Query OK, 0 rows affected (0.01 sec)
//////////
//////////mysql> select * from account;
//////////+----+--------+---------+
//////////        | id | name   | balance |
//////////        +----+--------+---------+
//////////        |  1 | 张三   |     900 |
//////////        |  2 | 李四   |    1000 |
//////////        +----+--------+---------+
//////////        2 rows in set (0.00 sec)
//////////
//////////mysql> start transaction;
//////////Query OK, 0 rows affected (0.00 sec)
//////////
//////////mysql> select * from account;
//////////+----+--------+---------+
//////////        | id | name   | balance |
//////////        +----+--------+---------+
//////////        |  1 | 张三   |     900 |
//////////        |  2 | 李四   |    1000 |
//////////        +----+--------+---------+
//////////        2 rows in set (0.00 sec)
//////////
//////////mysql> set savepoint sp1;
//////////ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'sp1' at line 1
//////////mysql> savepoint sp1;
//////////Query OK, 0 rows affected (0.00 sec)
//////////
//////////mysql> insert into account values (null, '王五', 600);
//////////Query OK, 1 row affected (0.00 sec)
//////////
//////////mysql> select * form account;
//////////ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'form account' at line 1
//////////mysql> select * from account;
//////////+----+--------+---------+
//////////        | id | name   | balance |
//////////        +----+--------+---------+
//////////        |  1 | 张三   |     900 |
//////////        |  2 | 李四   |    1000 |
//////////        |  3 | 王五   |     600 |
//////////        +----+--------+---------+
//////////        3 rows in set (0.00 sec)
//////////
//////////mysql> savepoint sp2;
//////////Query OK, 0 rows affected (0.00 sec)
//////////
//////////mysql> insert into account values (null, '赵六', 2000);
//////////Query OK, 1 row affected (0.00 sec)
//////////
//////////mysql> select * from accountl
//////////    -> ^C
//////////mysql> select * from account;
//////////+----+--------+---------+
//////////        | id | name   | balance |
//////////        +----+--------+---------+
//////////        |  1 | 张三   |     900 |
//////////        |  2 | 李四   |    1000 |
//////////        |  3 | 王五   |     600 |
//////////        |  4 | 赵六   |    2000 |
//////////        +----+--------+---------+
//////////        4 rows in set (0.00 sec)
//////////
//////////mysql> rollback sp1;
//////////ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'sp1' at line 1
//////////mysql> rollback to sp1;
//////////Query OK, 0 rows affected (0.00 sec)
//////////
//////////mysql> select * from account;
//////////+----+--------+---------+
//////////        | id | name   | balance |
//////////        +----+--------+---------+
//////////        |  1 | 张三   |     900 |
//////////        |  2 | 李四   |    1000 |
//////////        +----+--------+---------+
//////////        2 rows in set (0.00 sec)
//////////
//////////mysql> insert into account values (null, '王五', 600);
//////////Query OK, 1 row affected (0.00 sec)
//////////
//////////mysql> insert into account values (null, '赵六', 2000);
//////////Query OK, 1 row affected (0.00 sec)
//////////
//////////mysql> rollback to sp2;
//////////ERROR 1305 (42000): SAVEPOINT sp2 does not exist
//////////mysql> rollback to sp1;
//////////Query OK, 0 rows affected (0.00 sec)
//////////
//////////mysql> select * from account;
//////////+----+--------+---------+
//////////        | id | name   | balance |
//////////        +----+--------+---------+
//////////        |  1 | 张三   |     900 |
//////////        |  2 | 李四   |    1000 |
//////////        +----+--------+---------+
//////////        2 rows in set (0.00 sec)
//////////
//////////mysql> insert into account values (null, '王五', 600);
//////////Query OK, 1 row affected (0.00 sec)
//////////
//////////mysql> insert into account values (null, '赵六', 2000);
//////////Query OK, 1 row affected (0.00 sec)
//////////
//////////mysql> select * from account;
//////////+----+--------+---------+
//////////        | id | name   | balance |
//////////        +----+--------+---------+
//////////        |  1 | 张三   |     900 |
//////////        |  2 | 李四   |    1000 |
//////////        |  7 | 王五   |     600 |
//////////        |  8 | 赵六   |    2000 |
//////////        +----+--------+---------+
//////////        4 rows in set (0.00 sec)
//////////
//////////mysql> ^A
////////
////////Enter password: *********
////////Welcome to the MySQL monitor.  Commands end with ; or \g.
////////Your MySQL connection id is 12
////////Server version: 8.0.39 MySQL Community Server - GPL
////////
////////Copyright (c) 2000, 2024, Oracle and/or its affiliates.
////////
////////Oracle is a registered trademark of Oracle Corporation and/or its
////////affiliates. Other names may be trademarks of their respective
////////owners.
////////
////////        Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
////////
////////mysql> use java113;
////////Database changed
////////mysql> show tables;
////////+----------------------------------+
////////        | Tables_in_java113                |
////////        +----------------------------------+
////////        | account                          |
////////        | class                            |
////////        | course                           |
////////        | emp                              |
////////        | score                            |
////////        | stu2                             |
////////        | student                          |
////////        | test1                            |
////////        | test2                            |
////////        | test3                            |
////////        | test4                            |
////////        | view_student_class_course_score1 |
////////        +----------------------------------+
////////        12 rows in set (0.00 sec)
////////
////////mysql> select * from account;
////////+----+--------+---------+
////////        | id | name   | balance |
////////        +----+--------+---------+
////////        |  1 | 张三   |     900 |
////////        |  2 | 李四   |    1000 |
////////        +----+--------+---------+
////////        2 rows in set (0.00 sec)
////////
////////mysql> show variables like 'autocommit';
////////        +---------------+-------+
////////        | Variable_name | Value |
////////        +---------------+-------+
////////        | autocommit    | ON    |
////////        +---------------+-------+
////////        1 row in set, 1 warning (0.00 sec)
////////
////////mysql> set autocommit = 1;
////////Query OK, 0 rows affected (0.01 sec)
////////
////////mysql> show variables like 'autocommit';
////////        +---------------+-------+
////////        | Variable_name | Value |
////////        +---------------+-------+
////////        | autocommit    | ON    |
////////        +---------------+-------+
////////        1 row in set, 1 warning (0.00 sec)
////////
////////mysql> start transaction;
////////Query OK, 0 rows affected (0.00 sec)
////////
////////mysql> insert into account values (null, '王五', 2000);
////////Query OK, 1 row affected (0.00 sec)
////////
////////mysql> select * from acount;
////////ERROR 1146 (42S02): Table 'java113.acount' doesn't exist
////////mysql> select * from account;
////////+----+--------+---------+
////////        | id | name   | balance |
////////        +----+--------+---------+
////////        |  1 | 张三   |     900 |
////////        |  2 | 李四   |    1000 |
////////        |  9 | 王五   |    2000 |
////////        +----+--------+---------+
////////        3 rows in set (0.00 sec)
////////
////////mysql>
//////
//////Enter password: *********
//////Welcome to the MySQL monitor.  Commands end with ; or \g.
//////Your MySQL connection id is 13
//////Server version: 8.0.39 MySQL Community Server - GPL
//////
//////Copyright (c) 2000, 2024, Oracle and/or its affiliates.
//////
//////Oracle is a registered trademark of Oracle Corporation and/or its
//////affiliates. Other names may be trademarks of their respective
//////owners.
//////
//////        Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
//////
//////mysql> use java113;
//////Database changed
//////mysql> select * from account;
//////+----+--------+---------+
//////        | id | name   | balance |
//////        +----+--------+---------+
//////        |  1 | 张三   |     900 |
//////        |  2 | 李四   |    1000 |
//////        +----+--------+---------+
//////        2 rows in set (0.00 sec)
//////
//////mysql> select * from account;
//////+----+--------+---------+
//////        | id | name   | balance |
//////        +----+--------+---------+
//////        |  1 | 张三   |     900 |
//////        |  2 | 李四   |    1000 |
//////        +----+--------+---------+
//////        2 rows in set (0.00 sec)
//////
//////mysql> select @@global.transaction_isolation;
//////+--------------------------------+
//////        | @@global.transaction_isolation |
//////        +--------------------------------+
//////        | REPEATABLE-READ                |
//////        +--------------------------------+
//////        1 row in set (0.00 sec)
//////
//////mysql> set transaction isolattion level read uncommitted;
//////ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'isolattion level read uncommitted' at line 1
//////mysql> set transaction isolation level read uncommitted;
//////Query OK, 0 rows affected (0.00 sec)
//////
//////mysql> insert into account values (null, '王五', 2000);
//////Query OK, 1 row affected (0.03 sec)
//////
//////mysql> rollback;
//////Query OK, 0 rows affected (0.00 sec)
//////
//////mysql> select * from account;
//////+----+--------+---------+
//////        | id | name   | balance |
//////        +----+--------+---------+
//////        |  1 | 张三   |     900 |
//////        |  2 | 李四   |    1000 |
//////        | 10 | 王五   |    2000 |
//////        +----+--------+---------+
//////        3 rows in set (0.00 sec)
//////
//////mysql> start transaction;
//////Query OK, 0 rows affected (0.00 sec)
//////
//////mysql> insert into account values (null, '赵六', 200);
//////Query OK, 1 row affected (0.00 sec)
//////
//////mysql> select * from account;
//////+----+--------+---------+
//////        | id | name   | balance |
//////        +----+--------+---------+
//////        |  1 | 张三   |     900 |
//////        |  2 | 李四   |    1000 |
//////        | 10 | 王五   |    2000 |
//////        | 11 | 赵六   |     200 |
//////        +----+--------+---------+
//////        4 rows in set (0.00 sec)
//////
//////mysql> select @@global.transaction_isolation;
//////+--------------------------------+
//////        | @@global.transaction_isolation |
//////        +--------------------------------+
//////        | REPEATABLE-READ                |
//////        +--------------------------------+
//////        1 row in set (0.00 sec)
//////
//////mysql> set transaction isolation level read uncommitted;
//////ERROR 1568 (25001): Transaction characteristics can't be changed while a transaction is in progress
//////mysql> commit;
//////Query OK, 0 rows affected (0.00 sec)
//////
//////mysql> set transaction isolation level read uncommitted;
//////Query OK, 0 rows affected (0.00 sec)
//////
//////mysql> select @@blobal.transaction_isolation;
//////ERROR 1193 (HY000): Unknown system variable 'blobal.transaction_isolation'
//////mysql> select @@global.transaction_isolation;
//////+--------------------------------+
//////        | @@global.transaction_isolation |
//////        +--------------------------------+
//////        | REPEATABLE-READ                |
//////        +--------------------------------+
//////        1 row in set (0.00 sec)
//////
//////mysql> select @@session.transaction_isolation;
//////+---------------------------------+
//////        | @@session.transaction_isolation |
//////        +---------------------------------+
//////        | REPEATABLE-READ                 |
//////        +---------------------------------+
//////        1 row in set (0.00 sec)
//////
//////mysql> start transcation;
//////ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'transcation' at line 1
//////mysql> start transaction;
//////Query OK, 0 rows affected (0.00 sec)
//////
//////mysql> select @@session.transaction_isolation;
//////+---------------------------------+
//////        | @@session.transaction_isolation |
//////        +---------------------------------+
//////        | REPEATABLE-READ                 |
//////        +---------------------------------+
//////        1 row in set (0.00 sec)
//////
//////mysql> commit;
//////Query OK, 0 rows affected (0.00 sec)
//////
//////mysql> select @@session.transaction_isolation;
//////+---------------------------------+
//////        | @@session.transaction_isolation |
//////        +---------------------------------+
//////        | REPEATABLE-READ                 |
//////        +---------------------------------+
//////        1 row in set (0.00 sec)
//////
//////mysql> set session transaction isolation level read uncommitted;
//////Query OK, 0 rows affected (0.01 sec)
//////
//////mysql> set session transaction isolation level read uncommitted;
//////Query OK, 0 rows affected (0.00 sec)
//////
//////mysql> select @@session.transaction_isolation;
//////+---------------------------------+
//////        | @@session.transaction_isolation |
//////        +---------------------------------+
//////        | READ-UNCOMMITTED                |
//////        +---------------------------------+
//////        1 row in set (0.00 sec)
//////
//////mysql> start transaction;
//////Query OK, 0 rows affected (0.00 sec)
//////
//////mysql> insert into account values (null, '钱七', 3000);
//////Query OK, 1 row affected (0.00 sec)
//////
//////mysql> select * from account;
//////+----+--------+---------+
//////        | id | name   | balance |
//////        +----+--------+---------+
//////        |  1 | 张三   |     900 |
//////        |  2 | 李四   |    1000 |
//////        | 10 | 王五   |    2000 |
//////        | 11 | 赵六   |     200 |
//////        | 12 | 钱七   |    3000 |
//////        +----+--------+---------+
//////        5 rows in set (0.00 sec)
//////
//////mysql> rollback;
//////Query OK, 0 rows affected (0.01 sec)
//////
//////mysql> select @@session.transaction_isolation;
//////+---------------------------------+
//////        | @@session.transaction_isolation |
//////        +---------------------------------+
//////        | READ-UNCOMMITTED                |
//////        +---------------------------------+
//////        1 row in set (0.00 sec)
//////
//////mysql> set global transaction isolation level read uncommitted;
//////Query OK, 0 rows affected (0.00 sec)
//////
//////mysql> select @@session.transaction_isolation;
//////+---------------------------------+
//////        | @@session.transaction_isolation |
//////        +---------------------------------+
//////        | READ-UNCOMMITTED                |
//////        +---------------------------------+
//////        1 row in set (0.00 sec)
//////
//////mysql> select @@global.transaction_isolation;
//////+--------------------------------+
//////        | @@global.transaction_isolation |
//////        +--------------------------------+
//////        | READ-UNCOMMITTED               |
//////        +--------------------------------+
//////        1 row in set (0.00 sec)
//////
//////mysql> select * from account;
//////+----+--------+---------+
//////        | id | name   | balance |
//////        +----+--------+---------+
//////        |  1 | 张三   |     900 |
//////        |  2 | 李四   |    1000 |
//////        | 10 | 王五   |    2000 |
//////        | 11 | 赵六   |     200 |
//////        +----+--------+---------+
//////        4 rows in set (0.00 sec)
//////
//////mysql> start transaction;
//////Query OK, 0 rows affected (0.00 sec)
//////
//////mysql> insert into account values (null, '钱七', 3000);
//////Query OK, 1 row affected (0.00 sec)
//////
//////mysql> select * from account;
//////+----+--------+---------+
//////        | id | name   | balance |
//////        +----+--------+---------+
//////        |  1 | 张三   |     900 |
//////        |  2 | 李四   |    1000 |
//////        | 10 | 王五   |    2000 |
//////        | 11 | 赵六   |     200 |
//////        | 13 | 钱七   |    3000 |
//////        +----+--------+---------+
//////        5 rows in set (0.00 sec)
//////
//////mysql>
////
////Enter password: *********
////Welcome to the MySQL monitor.  Commands end with ; or \g.
////Your MySQL connection id is 14
////Server version: 8.0.39 MySQL Community Server - GPL
////
////Copyright (c) 2000, 2024, Oracle and/or its affiliates.
////
////Oracle is a registered trademark of Oracle Corporation and/or its
////affiliates. Other names may be trademarks of their respective
////owners.
////
////        Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
////
////mysql> use java113;
////Database changed
////mysql> select * from accountl
////    -> ^C
////mysql> select * from account;
////+----+--------+---------+
////        | id | name   | balance |
////        +----+--------+---------+
////        |  1 | 张三   |     900 |
////        |  2 | 李四   |    1000 |
////        | 10 | 王五   |    2000 |
////        +----+--------+---------+
////        3 rows in set (0.00 sec)
////
////mysql> select * from account;
////+----+--------+---------+
////        | id | name   | balance |
////        +----+--------+---------+
////        |  1 | 张三   |     900 |
////        |  2 | 李四   |    1000 |
////        | 10 | 王五   |    2000 |
////        +----+--------+---------+
////        3 rows in set (0.00 sec)
////
////mysql> select * from account;
////+----+--------+---------+
////        | id | name   | balance |
////        +----+--------+---------+
////        |  1 | 张三   |     900 |
////        |  2 | 李四   |    1000 |
////        | 10 | 王五   |    2000 |
////        +----+--------+---------+
////        3 rows in set (0.00 sec)
////
////mysql> select * from account;
////+----+--------+---------+
////        | id | name   | balance |
////        +----+--------+---------+
////        |  1 | 张三   |     900 |
////        |  2 | 李四   |    1000 |
////        | 10 | 王五   |    2000 |
////        | 11 | 赵六   |     200 |
////        +----+--------+---------+
////        4 rows in set (0.00 sec)
////
////mysql> select * from account;
////+----+--------+---------+
////        | id | name   | balance |
////        +----+--------+---------+
////        |  1 | 张三   |     900 |
////        |  2 | 李四   |    1000 |
////        | 10 | 王五   |    2000 |
////        | 11 | 赵六   |     200 |
////        +----+--------+---------+
////        4 rows in set (0.00 sec)
////
////mysql> select @@session.transaction_isolation;
////+---------------------------------+
////        | @@session.transaction_isolation |
////        +---------------------------------+
////        | REPEATABLE-READ                 |
////        +---------------------------------+
////        1 row in set (0.00 sec)
////
////mysql> select @@global.transaction_isolation;
////+--------------------------------+
////        | @@global.transaction_isolation |
////        +--------------------------------+
////        | READ-UNCOMMITTED               |
////        +--------------------------------+
////        1 row in set (0.00 sec)
////
////mysql> select * from account;
////+----+--------+---------+
////        | id | name   | balance |
////        +----+--------+---------+
////        |  1 | 张三   |     900 |
////        |  2 | 李四   |    1000 |
////        | 10 | 王五   |    2000 |
////        | 11 | 赵六   |     200 |
////        +----+--------+---------+
////        4 rows in set (0.00 sec)
////
////mysql> start transcation;
////ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'transcation' at line 1
////mysql> select * from account;
////+----+--------+---------+
////        | id | name   | balance |
////        +----+--------+---------+
////        |  1 | 张三   |     900 |
////        |  2 | 李四   |    1000 |
////        | 10 | 王五   |    2000 |
////        | 11 | 赵六   |     200 |
////        +----+--------+---------+
////        4 rows in set (0.00 sec)
////
////mysql>
//
//Enter password: *********
//Welcome to the MySQL monitor.  Commands end with ; or \g.
//Your MySQL connection id is 13
//Server version: 8.0.39 MySQL Community Server - GPL
//
//Copyright (c) 2000, 2024, Oracle and/or its affiliates.
//
//Oracle is a registered trademark of Oracle Corporation and/or its
//affiliates. Other names may be trademarks of their respective
//owners.
//
//        Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
//
//mysql> use java113;
//Database changed
//mysql> select * from account;
//+----+--------+---------+
//        | id | name   | balance |
//        +----+--------+---------+
//        |  1 | 张三   |     900 |
//        |  2 | 李四   |    1000 |
//        +----+--------+---------+
//        2 rows in set (0.00 sec)
//
//mysql> select * from account;
//+----+--------+---------+
//        | id | name   | balance |
//        +----+--------+---------+
//        |  1 | 张三   |     900 |
//        |  2 | 李四   |    1000 |
//        +----+--------+---------+
//        2 rows in set (0.00 sec)
//
//mysql> select @@global.transaction_isolation;
//+--------------------------------+
//        | @@global.transaction_isolation |
//        +--------------------------------+
//        | REPEATABLE-READ                |
//        +--------------------------------+
//        1 row in set (0.00 sec)
//
//mysql> set transaction isolattion level read uncommitted;
//ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'isolattion level read uncommitted' at line 1
//mysql> set transaction isolation level read uncommitted;
//Query OK, 0 rows affected (0.00 sec)
//
//mysql> insert into account values (null, '王五', 2000);
//Query OK, 1 row affected (0.03 sec)
//
//mysql> rollback;
//Query OK, 0 rows affected (0.00 sec)
//
//mysql> select * from account;
//+----+--------+---------+
//        | id | name   | balance |
//        +----+--------+---------+
//        |  1 | 张三   |     900 |
//        |  2 | 李四   |    1000 |
//        | 10 | 王五   |    2000 |
//        +----+--------+---------+
//        3 rows in set (0.00 sec)
//
//mysql> start transaction;
//Query OK, 0 rows affected (0.00 sec)
//
//mysql> insert into account values (null, '赵六', 200);
//Query OK, 1 row affected (0.00 sec)
//
//mysql> select * from account;
//+----+--------+---------+
//        | id | name   | balance |
//        +----+--------+---------+
//        |  1 | 张三   |     900 |
//        |  2 | 李四   |    1000 |
//        | 10 | 王五   |    2000 |
//        | 11 | 赵六   |     200 |
//        +----+--------+---------+
//        4 rows in set (0.00 sec)
//
//mysql> select @@global.transaction_isolation;
//+--------------------------------+
//        | @@global.transaction_isolation |
//        +--------------------------------+
//        | REPEATABLE-READ                |
//        +--------------------------------+
//        1 row in set (0.00 sec)
//
//mysql> set transaction isolation level read uncommitted;
//ERROR 1568 (25001): Transaction characteristics can't be changed while a transaction is in progress
//mysql> commit;
//Query OK, 0 rows affected (0.00 sec)
//
//mysql> set transaction isolation level read uncommitted;
//Query OK, 0 rows affected (0.00 sec)
//
//mysql> select @@blobal.transaction_isolation;
//ERROR 1193 (HY000): Unknown system variable 'blobal.transaction_isolation'
//mysql> select @@global.transaction_isolation;
//+--------------------------------+
//        | @@global.transaction_isolation |
//        +--------------------------------+
//        | REPEATABLE-READ                |
//        +--------------------------------+
//        1 row in set (0.00 sec)
//
//mysql> select @@session.transaction_isolation;
//+---------------------------------+
//        | @@session.transaction_isolation |
//        +---------------------------------+
//        | REPEATABLE-READ                 |
//        +---------------------------------+
//        1 row in set (0.00 sec)
//
//mysql> start transcation;
//ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'transcation' at line 1
//mysql> start transaction;
//Query OK, 0 rows affected (0.00 sec)
//
//mysql> select @@session.transaction_isolation;
//+---------------------------------+
//        | @@session.transaction_isolation |
//        +---------------------------------+
//        | REPEATABLE-READ                 |
//        +---------------------------------+
//        1 row in set (0.00 sec)
//
//mysql> commit;
//Query OK, 0 rows affected (0.00 sec)
//
//mysql> select @@session.transaction_isolation;
//+---------------------------------+
//        | @@session.transaction_isolation |
//        +---------------------------------+
//        | REPEATABLE-READ                 |
//        +---------------------------------+
//        1 row in set (0.00 sec)
//
//mysql> set session transaction isolation level read uncommitted;
//Query OK, 0 rows affected (0.01 sec)
//
//mysql> set session transaction isolation level read uncommitted;
//Query OK, 0 rows affected (0.00 sec)
//
//mysql> select @@session.transaction_isolation;
//+---------------------------------+
//        | @@session.transaction_isolation |
//        +---------------------------------+
//        | READ-UNCOMMITTED                |
//        +---------------------------------+
//        1 row in set (0.00 sec)
//
//mysql> start transaction;
//Query OK, 0 rows affected (0.00 sec)
//
//mysql> insert into account values (null, '钱七', 3000);
//Query OK, 1 row affected (0.00 sec)
//
//mysql> select * from account;
//+----+--------+---------+
//        | id | name   | balance |
//        +----+--------+---------+
//        |  1 | 张三   |     900 |
//        |  2 | 李四   |    1000 |
//        | 10 | 王五   |    2000 |
//        | 11 | 赵六   |     200 |
//        | 12 | 钱七   |    3000 |
//        +----+--------+---------+
//        5 rows in set (0.00 sec)
//
//mysql> rollback;
//Query OK, 0 rows affected (0.01 sec)
//
//mysql> select @@session.transaction_isolation;
//+---------------------------------+
//        | @@session.transaction_isolation |
//        +---------------------------------+
//        | READ-UNCOMMITTED                |
//        +---------------------------------+
//        1 row in set (0.00 sec)
//
//mysql> set global transaction isolation level read uncommitted;
//Query OK, 0 rows affected (0.00 sec)
//
//mysql> select @@session.transaction_isolation;
//+---------------------------------+
//        | @@session.transaction_isolation |
//        +---------------------------------+
//        | READ-UNCOMMITTED                |
//        +---------------------------------+
//        1 row in set (0.00 sec)
//
//mysql> select @@global.transaction_isolation;
//+--------------------------------+
//        | @@global.transaction_isolation |
//        +--------------------------------+
//        | READ-UNCOMMITTED               |
//        +--------------------------------+
//        1 row in set (0.00 sec)
//
//mysql> select * from account;
//+----+--------+---------+
//        | id | name   | balance |
//        +----+--------+---------+
//        |  1 | 张三   |     900 |
//        |  2 | 李四   |    1000 |
//        | 10 | 王五   |    2000 |
//        | 11 | 赵六   |     200 |
//        +----+--------+---------+
//        4 rows in set (0.00 sec)
//
//mysql> start transaction;
//Query OK, 0 rows affected (0.00 sec)
//
//mysql> insert into account values (null, '钱七', 3000);
//Query OK, 1 row affected (0.00 sec)
//
//mysql> select * from account;
//+----+--------+---------+
//        | id | name   | balance |
//        +----+--------+---------+
//        |  1 | 张三   |     900 |
//        |  2 | 李四   |    1000 |
//        | 10 | 王五   |    2000 |
//        | 11 | 赵六   |     200 |
//        | 13 | 钱七   |    3000 |
//        +----+--------+---------+
//        5 rows in set (0.00 sec)
//
//mysql> select @@global.transaction_isolation;
//+--------------------------------+
//        | @@global.transaction_isolation |
//        +--------------------------------+
//        | READ-UNCOMMITTED               |
//        +--------------------------------+
//        1 row in set (0.00 sec)
//
//mysql> commit;
//Query OK, 0 rows affected (0.01 sec)
//
//mysql> select @@global.transaction_isolation;\
//        +--------------------------------+
//        | @@global.transaction_isolation |
//        +--------------------------------+
//        | READ-UNCOMMITTED               |
//        +--------------------------------+
//        1 row in set (0.00 sec)
//
//mysql> start transaction;
//Query OK, 0 rows affected (0.00 sec)
//
//mysql>
//mysql> select * from account;
//+----+--------+---------+
//        | id | name   | balance |
//        +----+--------+---------+
//        |  1 | 张三   |     900 |
//        |  2 | 李四   |    1000 |
//        | 10 | 王五   |    2000 |
//        | 11 | 赵六   |     200 |
//        | 13 | 钱七   |    3000 |
//        +----+--------+---------+
//        5 rows in set (0.00 sec)
//
//mysql> delete from account where name = '赵六' or name = '钱七';
//Query OK, 2 rows affected (0.03 sec)
//
//mysql> select * from account;
//+----+--------+---------+
//        | id | name   | balance |
//        +----+--------+---------+
//        |  1 | 张三   |     900 |
//        |  2 | 李四   |    1000 |
//        | 10 | 王五   |    2000 |
//        +----+--------+---------+
//        3 rows in set (0.00 sec)
//
//mysql> commit;
//Query OK, 0 rows affected (0.01 sec)
//
//mysql> start transaction;
//Query OK, 0 rows affected (0.00 sec)
//
//mysql> insert into account values (null, '赵六', 100);
//Query OK, 1 row affected (0.00 sec)
//
//mysql> select * from account;
//+----+--------+---------+
//        | id | name   | balance |
//        +----+--------+---------+
//        |  1 | 张三   |     900 |
//        |  2 | 李四   |    1000 |
//        | 10 | 王五   |    2000 |
//        | 14 | 赵六   |     100 |
//        +----+--------+---------+
//        4 rows in set (0.00 sec)
//
//mysql> delete from account where name = '赵六';
//Query OK, 1 row affected (0.00 sec)
//
//mysql> select * from account;
//+----+--------+---------+
//        | id | name   | balance |
//        +----+--------+---------+
//        |  1 | 张三   |     900 |
//        |  2 | 李四   |    1000 |
//        | 10 | 王五   |    2000 |
//        +----+--------+---------+
//        3 rows in set (0.00 sec)
//
//mysql> commit;
//Query OK, 0 rows affected (0.01 sec)
//
//mysql> SET GLOBAL TRANSACTION ISOLATION LEVEL READ UNCOMMITTED;
//Query OK, 0 rows affected (0.00 sec)
//
//mysql> select @@global.transaction_isolation;
//+--------------------------------+
//        | @@global.transaction_isolation |
//        +--------------------------------+
//        | READ-UNCOMMITTED               |
//        +--------------------------------+
//        1 row in set (0.00 sec)
//
//mysql> start transaction;
//Query OK, 0 rows affected (0.00 sec)
//
//mysql> insert into account values (null, '赵六', 100);
//Query OK, 1 row affected (0.00 sec)
//
//mysql> select * from account;
//+----+--------+---------+
//        | id | name   | balance |
//        +----+--------+---------+
//        |  1 | 张三   |     900 |
//        |  2 | 李四   |    1000 |
//        | 10 | 王五   |    2000 |
//        | 15 | 赵六   |     100 |
//        +----+--------+---------+
//        4 rows in set (0.00 sec)
//
//mysql>
//
//
//Enter password: *********
//Welcome to the MySQL monitor.  Commands end with ; or \g.
//Your MySQL connection id is 14
//Server version: 8.0.39 MySQL Community Server - GPL
//
//Copyright (c) 2000, 2024, Oracle and/or its affiliates.
//
//Oracle is a registered trademark of Oracle Corporation and/or its
//affiliates. Other names may be trademarks of their respective
//owners.
//
//        Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
//
//mysql> use java113;
//Database changed
//mysql> select * from accountl
//    -> ^C
//mysql> select * from account;
//+----+--------+---------+
//        | id | name   | balance |
//        +----+--------+---------+
//        |  1 | 张三   |     900 |
//        |  2 | 李四   |    1000 |
//        | 10 | 王五   |    2000 |
//        +----+--------+---------+
//        3 rows in set (0.00 sec)
//
//mysql> select * from account;
//+----+--------+---------+
//        | id | name   | balance |
//        +----+--------+---------+
//        |  1 | 张三   |     900 |
//        |  2 | 李四   |    1000 |
//        | 10 | 王五   |    2000 |
//        +----+--------+---------+
//        3 rows in set (0.00 sec)
//
//mysql> select * from account;
//+----+--------+---------+
//        | id | name   | balance |
//        +----+--------+---------+
//        |  1 | 张三   |     900 |
//        |  2 | 李四   |    1000 |
//        | 10 | 王五   |    2000 |
//        +----+--------+---------+
//        3 rows in set (0.00 sec)
//
//mysql> select * from account;
//+----+--------+---------+
//        | id | name   | balance |
//        +----+--------+---------+
//        |  1 | 张三   |     900 |
//        |  2 | 李四   |    1000 |
//        | 10 | 王五   |    2000 |
//        | 11 | 赵六   |     200 |
//        +----+--------+---------+
//        4 rows in set (0.00 sec)
//
//mysql> select * from account;
//+----+--------+---------+
//        | id | name   | balance |
//        +----+--------+---------+
//        |  1 | 张三   |     900 |
//        |  2 | 李四   |    1000 |
//        | 10 | 王五   |    2000 |
//        | 11 | 赵六   |     200 |
//        +----+--------+---------+
//        4 rows in set (0.00 sec)
//
//mysql> select @@session.transaction_isolation;
//+---------------------------------+
//        | @@session.transaction_isolation |
//        +---------------------------------+
//        | REPEATABLE-READ                 |
//        +---------------------------------+
//        1 row in set (0.00 sec)
//
//mysql> select @@global.transaction_isolation;
//+--------------------------------+
//        | @@global.transaction_isolation |
//        +--------------------------------+
//        | READ-UNCOMMITTED               |
//        +--------------------------------+
//        1 row in set (0.00 sec)
//
//mysql> select * from account;
//+----+--------+---------+
//        | id | name   | balance |
//        +----+--------+---------+
//        |  1 | 张三   |     900 |
//        |  2 | 李四   |    1000 |
//        | 10 | 王五   |    2000 |
//        | 11 | 赵六   |     200 |
//        +----+--------+---------+
//        4 rows in set (0.00 sec)
//
//mysql> start transcation;
//ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'transcation' at line 1
//mysql> select * from account;
//+----+--------+---------+
//        | id | name   | balance |
//        +----+--------+---------+
//        |  1 | 张三   |     900 |
//        |  2 | 李四   |    1000 |
//        | 10 | 王五   |    2000 |
//        | 11 | 赵六   |     200 |
//        +----+--------+---------+
//        4 rows in set (0.00 sec)
//
//mysql> start transaction;
//Query OK, 0 rows affected (0.00 sec)
//
//mysql> select * from account;
//+----+--------+---------+
//        | id | name   | balance |
//        +----+--------+---------+
//        |  1 | 张三   |     900 |
//        |  2 | 李四   |    1000 |
//        | 10 | 王五   |    2000 |
//        | 11 | 赵六   |     200 |
//        +----+--------+---------+
//        4 rows in set (0.00 sec)
//
//mysql> select @@global.transaction_isolation;
//+--------------------------------+
//        | @@global.transaction_isolation |
//        +--------------------------------+
//        | READ-UNCOMMITTED               |
//        +--------------------------------+
//        1 row in set (0.00 sec)
//
//mysql> select * from account;
//+----+--------+---------+
//        | id | name   | balance |
//        +----+--------+---------+
//        |  1 | 张三   |     900 |
//        |  2 | 李四   |    1000 |
//        | 10 | 王五   |    2000 |
//        | 11 | 赵六   |     200 |
//        +----+--------+---------+
//        4 rows in set (0.00 sec)
//
//mysql> select * from account;
//+----+--------+---------+
//        | id | name   | balance |
//        +----+--------+---------+
//        |  1 | 张三   |     900 |
//        |  2 | 李四   |    1000 |
//        | 10 | 王五   |    2000 |
//        | 11 | 赵六   |     200 |
//        +----+--------+---------+
//        4 rows in set (0.00 sec)
//
//mysql> commit;
//Query OK, 0 rows affected (0.00 sec)
//
//mysql> select * from account;
//+----+--------+---------+
//        | id | name   | balance |
//        +----+--------+---------+
//        |  1 | 张三   |     900 |
//        |  2 | 李四   |    1000 |
//        | 10 | 王五   |    2000 |
//        | 11 | 赵六   |     200 |
//        | 13 | 钱七   |    3000 |
//        +----+--------+---------+
//        5 rows in set (0.00 sec)
//
//mysql> select * from account;
//+----+--------+---------+
//        | id | name   | balance |
//        +----+--------+---------+
//        |  1 | 张三   |     900 |
//        |  2 | 李四   |    1000 |
//        | 10 | 王五   |    2000 |
//        | 11 | 赵六   |     200 |
//        | 13 | 钱七   |    3000 |
//        +----+--------+---------+
//        5 rows in set (0.00 sec)
//
//mysql> select * from account;
//+----+--------+---------+
//        | id | name   | balance |
//        +----+--------+---------+
//        |  1 | 张三   |     900 |
//        |  2 | 李四   |    1000 |
//        | 10 | 王五   |    2000 |
//        +----+--------+---------+
//        3 rows in set (0.00 sec)
//
//mysql> commit;
//Query OK, 0 rows affected (0.00 sec)
//
//mysql> transaction;
//ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'transaction' at line 1
//mysql> start transaction;
//Query OK, 0 rows affected (0.00 sec)
//
//mysql> select * from account;
//+----+--------+---------+
//        | id | name   | balance |
//        +----+--------+---------+
//        |  1 | 张三   |     900 |
//        |  2 | 李四   |    1000 |
//        | 10 | 王五   |    2000 |
//        +----+--------+---------+
//        3 rows in set (0.00 sec)
//
//mysql> select * from account;
//+----+--------+---------+
//        | id | name   | balance |
//        +----+--------+---------+
//        |  1 | 张三   |     900 |
//        |  2 | 李四   |    1000 |
//        | 10 | 王五   |    2000 |
//        +----+--------+---------+
//        3 rows in set (0.00 sec)
//
//mysql> commit;
//Query OK, 0 rows affected (0.00 sec)
//
//mysql> select @@global.transaction_isolation;
//+--------------------------------+
//        | @@global.transaction_isolation |
//        +--------------------------------+
//        | READ-UNCOMMITTED               |
//        +--------------------------------+
//        1 row in set (0.00 sec)
//
//mysql> start transaction;
//Query OK, 0 rows affected (0.00 sec)
//
//mysql> select * from account;
//+----+--------+---------+
//        | id | name   | balance |
//        +----+--------+---------+
//        |  1 | 张三   |     900 |
//        |  2 | 李四   |    1000 |
//        | 10 | 王五   |    2000 |
//        +----+--------+---------+
//        3 rows in set (0.00 sec)
//
//mysql> commit;
//Query OK, 0 rows affected (0.00 sec)
//
//mysql> start transaction;
//Query OK, 0 rows affected (0.00 sec)
//
//mysql> select * from account;
//+----+--------+---------+
//        | id | name   | balance |
//        +----+--------+---------+
//        |  1 | 张三   |     900 |
//        |  2 | 李四   |    1000 |
//        | 10 | 王五   |    2000 |
//        +----+--------+---------+
//        3 rows in set (0.00 sec)
//
//mysql>